1) Field
The general inventive concept relates to a method of scanning a biochip, and more particularly, to a method of scanning a biochip at a substantially improved speed.
2) Description of the Related Art
A biochip is a biometric device typically made by combining biogenic organic materials, such as enzymes, proteins, antibodies and deoxyribonucleic acid (“DNA”) of living creatures, microorganisms, and cells, organs and nerves of animals and plants, for example, into a microchip, which is similar to a semiconductor chip. More particularly, a DNA biochip, for example, is a device for detecting DNA, and is made by arranging several hundred to several hundred thousand types of DNA, which have different base sequences, and of which functions in cells are clarified, in a single spiral shape (instead of a double spiral shape) within a small space on a substrate, which may be a glass substrate or a semiconductor substrate, for example. Generally, a collection of single spiral shaped DNA having the same base sequence is referred to as a spot, and approximately twenty to thirty bases are typically connected to form a single spot. Similarly, in a protein biochip, a collection of antibodies or receptors, which may be combined with the same protein, is referred to as a spot.
When a sample is dropped onto a biochip, only a gene or a protein corresponding to a certain spot is combined with the spot, and genes or proteins which are not combined with spots on the biochip are washed away. Thus, genetic information of the sample is easily obtained by identifying spots on the biochip, which have combined with the sample. For example, aspects of unique genetic expressions or mutations in a certain cell or tissue are easily analyzed using the biochip. Also, the biochip may be used in massive analyses of genetic expressions, pathogenic bacteria infection tests, antibiotic-resistance tests, research on biological reactions with respect to environmental factors, food safety inspection, identification of criminals, development of new drugs and medical inspection of animals and plants, for example.
Various methods of identifying spots on a biochip, which are combined with genes of the sample dropped onto the biochip, have been suggested, and, specifically, a fluorescent detection method is one example. In the fluorescent detection method, a fluorescent material that emits light of a certain color when excited by excitation light is combined with the sample. The spots combined with the sample are identified by dropping the sample onto the biochip and then analyzing a fluorescent image obtained by projecting excitation light onto the biochip.
In general, a scanner device, which obtains the fluorescent image by projecting the excitation light onto a biochip, obtains the fluorescent image by scanning the biochip using a pixel size from about 5 micrometers (μm) to about 10 μm. A basic unit of scanning is referred as a panel, and a single biochip generally includes several hundred panels. In addition, several hundred to several hundred thousand spots form a microarray on a single panel. Generally, fluorescent images of individual panels are obtained by sequentially scanning the individual panels by moving the biochip and a camera of the scanner device. Thus, a single large biochip image is formed by connecting the individual fluorescent images of the panels. Accordingly, spots of the biochip, which are combined with the sample, are analyzed.
However, when a surface of a microarray of a biochip is tilted, a brightness and location of a fluorescent image is accurately obtained by focusing on each individual panel. However, this means that a high-density biochip, having a large number of panels, requires an excessive scanning time to focus on each panel. Also, when the microarray of the biochip is not accurately arranged, e.g., is not arranged in parallel with a moving axis of the camera of the scanner device, such as if the biochip is rotated, for example, portions of a fluorescent image are cut off and, thus, the entire fluorescent image cannot be scanned. Furthermore, it is tedious and inconvenient to rotate and connect fluorescent images of individual panels to form a single large biochip image, thereby substantially increasing a time required to analyze the sample.